This invention relates to a telephone terminal device with a function to perform the predetermined operation corresponding to speech signals by recognizing the speech signals from telephone transmitters.
As the telephone terminal device of this type is known, a telephone having a speech origination function is described below. That is, pieces of speech information are stored in a built-in memory by making comparisons to the telephone numbers in advance. When an originating call is made, a speech signal is input from the handset transmitter microphone, and it is checked against the speech information stored in the memory by means of the built-in speech recognition device. When, as a result of the checkup, the speech information corresponding to the input speech signal is found, the telephone number stored in correspondence to the speech information is read out and converted into a dial pulses or multi-frequency signals and then sent out to the telephone network (office line). At the time of the origination as above-mentioned, the handset is made to off-hook in order to enable the speech signal to be input from the microphone. When the handset is made to off-hook, the telephone network switch is automatically turned ON, and the telephone network is acquired. Once the network is acquired, the dial tone from the telephone office is sent through the circuit into this telephone terminal device and sent to the telephone receiver.
In the conventional telephone terminal device as explained above, part of the dial tone sent to the receiver enters the microphone through an acoustic coupling, and is thus sent to the speech recognition device in superposition on speech signals to the telephone transmitter, thus making the speech signal identification difficult. Further, the conventional telephone device is equipped for checking whether or not the speech recognition device is functioning normally. In this checkup operation, first the speech signal is input from the telephone transmitter, analyzed and verified with the speech recognition device, and when the speech information that corresponds to this speech signal is found, the speech data preset in the speech memory corresponding to this information is read out, reproduced and sent out to the receiver. At this time, since the dial tones from the telephone network enter the receiver together with the reproduced speech signals, these reproduced speech signals representing the recognition result become mixed with the dial tone, thus making them very hard to understand. Moreover, when in the registration of speech information and operation check of the speech recognition device, the ringing signal sounds by a call incoming while the receiver is receiving speech signals, the ringing signal enters the microphone, thus also causing of interference with registration and verification.